CN106251244A - Power distribution network transformation method considering comprehensive utilization rate of equipment - Google Patents

Abstract

Embodiments of the present invention provide a method for transforming a distribution network considering the comprehensive utilization rate of equipment, which relates to the field of power system planning, and can control the utilization rate of power grid equipment within a reasonable range, improve the operating efficiency of the power grid, and improve the security of the power grid. The specific solution includes: obtaining the description data of the distribution network to be transformed, determining the constraint conditions according to the description data; predicting the load forecast value of the grid equipment in the distribution network according to the description data, and value calculation to obtain the utilization rate of the grid equipment; according to the constraints and the utilization rate of the grid equipment, determine the identification information of the grid equipment to be transformed; the identification information includes the type of grid equipment to be transformed and the required meet the parameter requirements. The invention is used to provide technical analysis for distribution network reconstruction.

Description

A Distribution Network Transformation Method Considering the Comprehensive Utilization of Equipment

technical field

The invention relates to the field of power system planning, in particular to a method for transforming a distribution network considering the comprehensive utilization rate of equipment.

Background technique

With the development of the economy, the load of the power grid increases rapidly, and it is often necessary to transform the existing distribution network. From the perspective of power grid planning, the reasonable load capacity and actual utilization level of equipment should meet the constraints of the economic operation range of various equipment to ensure that planning and operation can be coordinated with each other.

In the existing distribution network transformation project, due to the inaccurate prediction of the power load in the planning stage, the inappropriate number or type selection of the main transformers in the substation, or the unreasonable network structure during operation, the distribution network transformation has problems. A certain blindness often leads to unreasonable utilization of power grid equipment, some equipment has low utilization, and some equipment has high utilization. If the utilization rate of equipment is too low, it will cause a waste of renovation costs, while if the utilization rate of equipment is too high, it will easily lead to safety problems.

Contents of the invention

Embodiments of the present invention provide a method for transforming a distribution network considering the comprehensive utilization rate of equipment, which can control the utilization rate of power grid equipment within a reasonable range, improve the operating efficiency of the power grid, and improve the security of the power grid. In order to achieve the above object, the present invention adopts following solutions:

In the first aspect, a distribution network transformation method considering the comprehensive utilization rate of equipment is provided, including:

Obtaining description data of the distribution network to be transformed, and determining constraint conditions according to the description data; the constraint conditions are used to indicate weak items of the distribution network that need to be transformed;

Predicting the load forecast value of the grid equipment in the distribution network according to the description data, and calculating the utilization rate of the grid equipment according to the load forecast value;

According to the constraints and the utilization rate of the power grid equipment, determine the identification information of the power grid equipment to be transformed; the identification information includes the type of the power grid equipment to be transformed and the parameter requirements to be achieved after transformation.

The distribution network transformation method provided by the embodiment of the present invention first obtains the description data of the distribution network, and the description data of the distribution network is the data about the distribution network obtained by the power measurement system, such as household power data, Scheduling operation data, geographic information system data, equipment detection and monitoring data, and fault repair data, etc. These data can provide detailed reference information for the expansion planning of distribution network. Further, the weak items that need to be transformed in the distribution network are determined, and the utilization rate of the power grid equipment in the distribution network is calculated. Here, the utilization rate of the grid equipment in the distribution network may refer to part or all of the grid equipment in the distribution network. Then determine which weak items to transform according to the utilization rate, including the type of power grid equipment that needs to be transformed and the parameter requirements to be achieved after transformation, so as to comprehensively and accurately control the utilization rate of power grid equipment in the distribution network within a reasonable range.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only of the present invention. For some embodiments, those of ordinary skill in the art can also obtain other drawings based on these drawings without any creative effort.

Fig. 1 is a schematic flow chart of a method for transforming a distribution network provided by an embodiment of the present invention;

Fig. 2 is a schematic structural diagram of a distribution network network exemplified in an embodiment of the present invention;

Fig. 3 is a schematic diagram of a typical daily load curve of a distribution network exemplified in an embodiment of the present invention.

detailed description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Example

Embodiments of the present invention provide a method for transforming a distribution network considering the comprehensive utilization rate of equipment, as shown in FIG. 1 , including the following steps:

101. Obtain description data of the distribution network to be transformed, and determine constraint conditions according to the description data.

Analyze the current situation of the distribution network. Including obtaining parameters and operating conditions of distribution network equipment and network based on description data. Evaluate the current power supply security level of the distribution network, and obtain a set of constraints that need to be solved. The following two steps 101-1 and 101-2 are used for illustration.

101-1. Obtain the parameters and operating conditions of the distribution network equipment and network based on the description data.

The descriptive data of the distribution network is the data about the distribution network acquired by the power measurement system, including but not limited to at least one of the following: (1) Text materials, such as municipal planning, economic analysis, power grid description, problem Analysis, electricity consumption data of distribution network users, etc. (2) Graphical data, such as obtaining the geographical wiring diagram of the power grid from the geographic information system (English full name: Geographic Information System, English abbreviation: GIS). (3) Attribute information, such as obtaining power grid parameters and structure, equipment attribute parameters, etc. from the management information system (English full name: Management Information Systems, English abbreviation: MIS). (4) Operation data, such as obtaining substation power and lines from the data acquisition and monitoring control system (full English name: Supervisory ControlAnd Data Acquisition, English abbreviation: SCADA) and advanced metering system (English full name: Advanced Metering Infrastructure, English abbreviation: AMI) Operating conditions, electricity load information, etc.

101-2. Based on the obtained description data, evaluate the current power supply security level of the distribution network to be transformed, and obtain the constraints that need to be resolved.

Constraints are used to indicate the weak links in the grid operation, that is, the weak items of the distribution network that need to be transformed. A set of constraint conditions is expressed as: G={g ₁ , g ₂ ,...,g _n }, where g _i is the constraint that needs to be resolved during the reconstruction process. The constraint set considers the power supply reliability of the N-1 criterion, the ability to transfer loads under fault conditions, the maximum continuous operating current constraint, and thermal stability constraints.

102. Predict load prediction values of power grid equipment in the distribution network according to the description data.

Distribution network power load demand forecasting, including aggregate, partition and space load forecasting. And further consider the N-1 situation and the load transfer situation to obtain the load distribution under different operation modes.

In a specific implementation manner, the trend extrapolation method is used to predict the mid-term and near-term loads, and historical data is used to perform trend extrapolation through various mathematical models, so as to obtain the total amount development law of the target time period.

Forecasting models and methods available in implementation include elastic coefficient method, time series, gray system, correlation analysis method and equal growth rate method, and there are no specific requirements for the forecasting model here.

Since there are many uncertain factors affecting load demand, load forecasting can be carried out in a variety of ways. During the implementation process, no less than two forecasting schemes can be formulated, and one of them will be finally selected as the basis for the transformation design of the distribution network.

103. Calculate the utilization rate of the power grid equipment according to the load forecast value.

Considering the impact of different operation modes on the utilization rate of power grid equipment, the calculation of the utilization rate of power grid equipment needs to determine the type of operation mode and comprehensively consider the impact of various operation modes on the utilization rate. The following two steps 103-1 and 103-2 are used to illustrate.

103-1. Determination of different operation modes of distribution network power supply.

The number of operating modes is the number of operating states of all links that make up the distribution network. The system operation is divided into normal operation state, maintenance state and fault operation state. The set of setting distribution network operation modes is denoted by A, A={A ¹ ,A ² ,A ³ }, where, is the set of normal operating states, Expressed as the i-th network topology and architecture, K ¹ is the total number of states, that is, the number of operating modes in the normal operating state. The collections of maintenance status and fault operating status distribution are respectively given by and Indicates that K ² is the number of power grid operating states in the case of condition-based maintenance, that is, the number of operating modes in the maintenance state; K ³ is the number of power grid operating states in the case of faults, that is, the number of operating modes in the fault operating state.

103-2. Obtaining the utilization index of power grid equipment.

In the normal operation state, the utilization rate of the grid equipment is calculated according to the average load of the grid equipment within a preset period of time.

The load average value is calculated according to the first formula.

The first formula is:

P _avg represents the average value of the load, P _t represents the load prediction value obtained in step 102, and T represents the preset duration. The process of further calculating the utilization rate will be described later.

In the maintenance state and fault operation state, the utilization rate of the power grid equipment is calculated according to the maximum load value of the power grid equipment within a preset time period.

The maximum load value is calculated according to the second formula.

The second formula is:

P _N-1 represents the maximum value of the load, α represents the standard deviation of the load carried by the grid equipment,

$\mathrm{<span\; class="notranslate">\; \&alpha;</span>}<span\; class="notranslate">\; =</span>\sqrt{\frac{{<span\; class="notranslate">\; \&Integral;</span>}_{\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; T</span>}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; v</span>}\mathrm{<span\; class="notranslate">\; g</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}}<span\; class="notranslate">\; .</span>$

Explanation of the utilization rate calculation process:

The utilization rate η _i of the i-th device in the power grid is calculated according to the third formula.

The third formula is:

Among them, K=K ¹ +K ² +K ³ , K represents the total number of operating modes of the distribution network, and the number of operating modes is the number of operating states of all links forming the distribution network. K ¹ represents the number of operating modes in the normal operating state. K ² represents the number of operating modes in the inspection state. K ³ represents the number of operating modes in the faulty operating state.

λ _k =T _k /T is the time proportion of the kth operation mode in the time period T,

T _k is the duration of the kth running mode;

ηik is the equipment utilization rate of the i-th equipment in the k-th operation mode,

R _ik is the power passing through the kth component obtained through power flow calculation in the kth operating mode.

Z _ik =S _ik ×C _ik , where S _ik is the nominal rated capacity of element i or the limit capacity that can be operated under overload in the k-th operation mode. C _ik is the component usage efficiency of component i in the kth operating mode.

η _i can evaluate the utilization rate of power grid equipment within a fixed period T, and the specific value of η _i depends on the length of the time period T selected during the evaluation and the actual power consumption of the equipment during this period of time.

The greater the effective equipment utilization rate _ηi , it means that in the same time period, the actual power of the grid equipment is more, the higher the utilization rate is, and the equipment can be fully utilized. η _i can fully consider the actual operation of the equipment, and can more comprehensively reflect the effective utilization rate of the equipment. In practical applications, it can be considered to collect equipment data in typical time periods in months/quarters/years, and calculate its The capacity factor of the segment at different times, thus reflecting the utilization of the equipment in that period.

104. According to the constraints and the utilization rate of the grid equipment, determine the identification information of the grid equipment to be transformed.

The identification information includes the type of power grid equipment to be transformed, that is, which power grid equipment needs to be transformed, and the identification information also includes the parameter requirements to be achieved after transformation, that is, what specifications the transformed power grid equipment needs to meet.

In a specific implementation manner, the utilization rate of the grid equipment and the balanced utilization rate of the grid equipment in the distribution network may be considered at the same time. The two goals of utilizing each grid equipment as efficiently as possible and balancing the load of all grid equipment as possible have been achieved. The following two steps 104-1 and 104-2 are used for illustration.

104-1. Determine the distribution network transformation plan set according to the equipment utilization rate.

The transformation scheme set may be a set composed of identification information of grid equipment to be transformed.

Specifically, on the basis of considering the constraint set G, for the components with the lowest utilization rate of grid equipment, choose to reduce the transformation investment, such as reducing the cross-sectional area of the line, or replacing small-capacity equipment. For equipment with high utilization rate and power supply bottleneck, increase the investment and replace it with equipment with larger capacity. Utilize each grid equipment as efficiently as possible, and keep the utilization rate of grid equipment within a reasonable range.

104-2. According to the balanced utilization rate of the grid equipment in the distribution network, the set of distribution network transformation schemes is screened.

The purpose of screening is to use all grid equipment as evenly as possible under the condition of using each grid equipment as efficiently as possible.

Optionally, according to the utilization rate of the grid equipment, the balanced utilization rate of the grid equipment in the distribution network is determined. According to the constraint conditions, the utilization rate of the grid equipment and the equilibrium utilization rate, a set of filtered transformation schemes is determined.

Specifically, the balanced utilization rate may be calculated according to the fourth formula.

The fourth formula is:

Index(X) represents the balanced utilization rate, and N represents the number of grid equipment in the distribution network.

Describe the sum of the total utilization of N devices in the system.

Describe a situation where utilization is as balanced as possible across devices.

C ₁ and C ₂ are two preset weight values respectively. When C ₁ =0, the goal of the fourth formula is to make all grid equipments be utilized in a balanced manner; when C ₂ =0, regardless of whether the equipments can be balanced, the total equipment utilization rate is the highest. Usually, the values of C ₁ and C ₂ can be 2 and 1 respectively.

Step 104-1 After obtaining the transformation plan set, calculate the equilibrium utilization rate according to 104-2, observe the improvement of the original equilibrium utilization rate value and the change of the utilization coefficient, until the transformation of any power grid equipment cannot improve the equilibrium utilization rate up to utilization.

At this time, it can be considered that the balanced utilization rate has reached the maximum value, and the set composed of identification information at this time can be regarded as a set of filtered transformation schemes.

105. Judging whether the transformation plan of the distribution network meets the economic and safety requirements.

According to the economic and safety requirements, the set of transformation schemes is further screened and optimized, and finally the identification information of the power grid equipment that meets the economic and safety requirements is determined. The economical requirements and safety requirements are explained separately below.

The first aspect is economical requirements. It is reflected in the need to meet the general constraints of investment. During implementation, the following formula can be used to confirm whether the economic requirements are met:

$\underset{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}}{<span\; class="notranslate">\; \&Sigma;</span>}}\frac{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; B</span>}}^{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; )</span>}{{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}^{<span\; class="notranslate">\; \&PlusMinus;</span>}<span\; class="notranslate">\; )</span>}^{{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}}}<span\; class="notranslate">\; \&le;</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}\mathrm{<span\; class="notranslate">\; v</span>}\mathrm{<span\; class="notranslate">\; e</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; t</span>}}$

In the formula, _Minvest is the total investment budget for grid transformation; r _a is the interest rate or discount rate of funds; y(i) is the number of years included in the i-th stage; It is the investment and construction cost of the k-1 stage grid expansion.

The second aspect is security requirements. The safety goal is reflected in meeting the N-1 check, short-circuit current calculation and other checks.

If the requirements of one of the above two aspects are not met, add the unsatisfied constraints to the constraint set G, update the constraints and jump to step 104, and re-formulate the distribution network transformation plan, according to the updated constraints and the utilization rate of the grid equipment, and update the grid equipment identification information until the grid equipment identification information meets the security requirements, and then jump to 106.

106. Predict the utilization rate η _i and the equilibrium utilization rate Index(X) of the power grid equipment in the transformed distribution network.

After the above screening steps, determine the transformation plan of the distribution network, and give the utilization rate η _i of the power grid equipment that may be realized after the transformation and the balanced utilization rate Index(X) of the entire system to indicate the effect that can be achieved after the transformation, and for Data support will be provided for further transformation in the future.

Based on the transformation method of the distribution network described in the above steps, a specific case will be described below.

Take the distribution network structure shown in Figure 2 as an example, including four 110kV lines and five transformers. Transformers T1-T3 belong to the same substation, among which T1 adopts the wiring mode of line-transformer group, T2 and T3 adopt the single-bus section wiring mode, and the low-voltage side of the three transformers are connected through the bus section circuit breaker. Transformers T4 and T5 are located in the same substation and are connected by single busbar. Line and transformer parameters are shown in Table 1 and Table 2.

Table 1 Example line data

Table 2 Case transformer data

Since the supplied load exceeds the original planning and design, the distribution network needs to be transformed through capacity expansion. There are two specific expansion plans. Plan 1 is to expand and transform lines L1-L4. Option 2 is to expand and transform the transformers T1-T5. The load curve of the typical day of the power distribution system is shown in Figure 3, and the power factor requirement of the maximum load of the system is set as

When analyzing the equilibrium state, it is necessary to analyze various fault conditions of the power distribution network to be processed, and summarize the corresponding equilibrium efficiency and equilibrium capacity. The expected accidents of the sample system can be analyzed, and the equipment utilization efficiency in some operating modes is shown in Table 3.

Table 3 Equipment utilization efficiency in some operating modes

It can be seen from Table 3 that in terms of equalization efficiency, the efficiency of line L3 and line L4 is relatively low, indicating that the purpose of making full use of these components has not been achieved under balanced conditions, which has a greater relationship with the different operating modes of the system. Line L1 and line The maximum available case of L2 can be considered well utilized and indicates that in a particular case, the operation is at the limit state. The comprehensive utilization efficiency of the transformer is relatively high, which is close to 90% on average. At the same time, it is considered that if multiple equipments are overhauled at the same time, or if some equipment is overhauled, and a fault occurs at this time, as shown in case 11, the transformer will bear a heavy load . According to the regulations of my country's medium-voltage distribution substation operation guidelines, when the maximum allowable overload factor of the main transformer exceeds 1.3, the allowable overload time should be less than 45 minutes. If the fault cannot be eliminated within the limited time, it is necessary to expand the transformer, so the expansion process should choose to transform the transformer, especially for the T4 transformer.

As a specific implementation, this method takes into account the different operating states and load conditions of the distribution network, and pursues the goal of utilizing each component equipment as efficiently as possible and utilizing all component equipment as balancedly as possible. The analysis helps to obtain the best expansion planning scheme, and provides an idea for the construction of distribution network.

The distribution network transformation method provided by the embodiment of the present invention first obtains the description data of the distribution network, and the description data of the distribution network is the data about the distribution network obtained by the power measurement system, such as household power data, Scheduling operation data, geographic information system data, equipment detection and monitoring data, and fault repair data, etc. These data can provide detailed reference information for the expansion planning of distribution network. Further, the weak items that need to be transformed in the distribution network are determined, and the utilization rate of the power grid equipment in the distribution network is calculated. Here, the utilization rate of the grid equipment in the distribution network may refer to part or all of the grid equipment in the distribution network. Then determine which weak items to transform according to the utilization rate, including the type of power grid equipment that needs to be transformed and the parameter requirements to be achieved after transformation, so as to comprehensively and accurately control the utilization rate of power grid equipment in the distribution network within a reasonable range.

Since the descriptive data of the distribution network is measured by the power measurement system, the final transformation plan can accurately solve the weak links in the operation and meet the needs of future power grid development.

In addition, the distribution network reconstruction method provided by the embodiments of the present invention, in the case of satisfying the constraint conditions, pursues the two goals of utilizing each grid equipment as efficiently as possible and utilizing all grid equipment as balanced as possible, which can effectively improve Grid operation efficiency.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone familiar with the technical field can easily think of changes or replacements within the technical scope disclosed in the present invention, and should cover all Within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (9)

1. A distribution network transformation method considering comprehensive utilization of equipment, characterized in that, comprising: Obtaining description data of the distribution network to be transformed, and determining constraint conditions according to the description data; the constraint conditions are used to indicate weak items of the distribution network that need to be transformed; Predicting the load forecast value of the grid equipment in the distribution network according to the description data, and calculating the utilization rate of the grid equipment according to the load forecast value; According to the constraints and the utilization rate of the power grid equipment, determine the identification information of the power grid equipment to be transformed; the identification information includes the type of the power grid equipment to be transformed and the parameter requirements to be achieved after transformation. 2. The distribution network reconstruction method according to claim 1, wherein said calculating the utilization rate of said grid equipment according to said load prediction value comprises: In a normal operating state, calculate the utilization rate of the grid equipment according to the average load value of the grid equipment within a preset period of time; In the maintenance state and the failure operation state, the utilization rate of the grid equipment is calculated according to the average load and the maximum value of the load of the grid equipment within a preset time period. 3. The distribution network transformation method according to claim 2, characterized in that, The average load value is calculated according to the first formula; the maximum load value is calculated according to the second formula; The first formula is: P _avg represents the average value of the load, P _t represents the predicted value of the load, and T represents the preset duration; The second formula is: P _N-1 represents the maximum value of the load, α represents the standard deviation of the load carried by the grid equipment, 4. The distribution network reconstruction method according to claim 3, wherein the calculation to obtain the utilization rate of the grid equipment includes: Calculate the utilization rate η _i of the i-th equipment of the power grid according to the third formula; The third formula is: Among them, K=K ¹ +K ² +K ³ , K represents the total number of operating modes of the distribution network, and the number of operating modes is the number of operating states of all links that make up the distribution network; K ¹ represents The number of operating modes in the normal operating state; K ² indicates the number of operating modes in the maintenance state; K ³ indicates the number of operating modes in the fault operating state; λ _k =T _k /T is the time proportion of the kth operation mode in the time period T, T _k is the duration of the kth running mode; _ηik is the equipment utilization rate of the i-th equipment in the k-th operating mode, R _ik is the power passing through the k-th component obtained through power flow calculation in the k-th operating mode; Z _ik ＝S _ik ×C _ik , where S _ik is the nominal rated capacity of component i or the limit capacity that can be overloaded in operation mode k; C _ik is the component usage of component i in operation mode k efficiency. 5. The distribution network reconstruction method according to claim 1, further comprising: determining the balanced utilization rate of the grid equipment in the distribution network according to the utilization rate of the grid equipment; The identification information is determined according to the constraints, the utilization rate of the grid equipment, and the balanced utilization rate. 6. The distribution network transformation method according to claim 5, wherein said determination of the balanced utilization rate of the grid equipment in the distribution network comprises: calculating the balanced utilization ratio according to a fourth formula; The fourth formula is: Wherein, Index (X) represents described balanced utilization rate, N represents the quantity of grid equipment in described distribution network, and C ₁ and C ₂ are respectively two preset weight values; The determining the identification information includes: determining the identification information when the balanced utilization rate reaches a maximum value. 7. The distribution network transformation method according to claim 1, characterized in that, after determining the identification information of the power grid equipment to be transformed, further comprising: Determine the identification information of the power grid equipment that needs to be transformed to meet the economic and safety requirements. 8. The distribution network transformation method according to claim 7, characterized in that, When the grid equipment identification information does not meet the security requirements, update the constraints according to the security requirements; According to the updated constraint condition and the utilization rate of the grid equipment, the grid equipment identification information is updated until the grid equipment identification information meets the security requirements. 9. The distribution network reconstruction method according to any one of claims 5-8, further comprising: Predict the utilization rate η _i and the equilibrium utilization rate Index(X) of the power grid equipment in the transformed distribution network.